JP7407805B2 - Terminals, wireless communication methods, base stations and systems - Google Patents

Description

The present disclosure relates to a user terminal and a wireless communication method in a next generation mobile communication system.

In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) has been specified for the purpose of higher data rates, lower delays, etc. (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) has been specified for the purpose of further increasing capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

Successor systems to LTE (for example, also referred to as 5th generation mobile communication system (5G), 5G plus (+), New Radio (NR), 3GPP Rel. 15 or later) are also being considered.

In the existing LTE system (for example, Rel. 8-12), frequency bands (licensed bands, licensed carriers, licensed component carriers, licensed component carriers, etc.) licensed to telecommunications carriers (operators) are used. The specifications have been developed with the assumption that it will be used exclusively in For example, 800 MHz, 1.7 GHz, 2 GHz, etc. are used as the license CC.

In addition, in the existing LTE system (for example, Rel. (also called unlicensed CC) is supported. The unlicensed band may be, for example, a 2.4 GHz band or a 5 GHz band in which Wi-Fi (registered trademark) and Bluetooth (registered trademark) can be used.

Specifically, Rel. 13 supports carrier aggregation (CA) that integrates a licensed band carrier (CC) and an unlicensed band carrier (CC). Communication performed using an unlicensed band as well as a licensed band in this manner is called License-Assisted Access (LAA).

3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

In future wireless communication systems (e.g., 5G, 5G+, NR, Rel. 15 and later), transmitting devices (e.g., base stations in the downlink (DL), user terminals in the uplink (UL)) will operate in unlicensed bands. Listening (Listen Before Talk (LBT), Clear Channel Assessment (CCA), Carrier Sense, It also performs channel sensing or channel access procedure (also called channel access procedure).

In order for such a wireless communication system to coexist with other systems in an unlicensed band, it is conceivable that such a wireless communication system follows regulations or requirements in the unlicensed band.

However, if the operation in the unlicensed band is not clearly determined, there is a risk that the operation in a specific communication situation will not comply with the rules, the efficiency of wireless resource usage will decrease, and appropriate communication will not be possible in the unlicensed band. be.

Therefore, one object of the present disclosure is to provide a user terminal and a wireless communication method that perform appropriate communication in an unlicensed band.

A terminal according to an aspect of the present disclosure includes a receiving unit that receives a first setting corresponding to one or more first search spaces and a second setting corresponding to one or more second search spaces; determining one configuration of the first configuration and the second configuration based on detection of a link control information (DCI) format; and determining a configuration of a physical downlink control channel (PDCCH) according to a search space corresponding to the configuration. and a control unit that controls monitoring , and the DCI format is used to indicate the length of time used for transmission in the shared spectrum .

According to one aspect of the present disclosure, appropriate communication can be performed in an unlicensed band.

FIG. 1 is a diagram illustrating an example of a first downlink transmission method. FIG. 2 is a diagram illustrating an example of the second downlink transmission method. FIG. 3 is a diagram illustrating an example of dynamic PDCCH monitoring. FIG. 4 is a diagram illustrating an example of PDCCH monitoring using two SS configurations. FIG. 5 is a diagram illustrating an example of PDCCH monitoring using three SS configurations. FIG. 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 7 is a diagram illustrating an example of the configuration of a base station according to an embodiment. FIG. 8 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. FIG. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment.

<Unlicensed band>
In unlicensed bands (for example, 2.4 GHz band and 5 GHz band), it is assumed that multiple systems such as Wi-Fi systems and systems that support LAA (LAA systems) coexist. Collision avoidance and/or interference control of transmissions between systems may be required.

For example, in a Wi-Fi system that uses unlicensed bands, Carrier Sense Multiple Access (CSMA)/Collision Avoidance (CA) is employed for the purpose of collision avoidance and/or interference control. In CSMA/CA, Distributed Access Inter Frame Space (DIFS) is provided for a predetermined period of time before transmission, and the transmitter transmits data after confirming that there is no other transmission signal (carrier sense). Also, after data transmission, it waits for ACKnowledgement (ACK) from the receiving device. If the transmitting device cannot receive an ACK within a predetermined time, it determines that a collision has occurred and retransmits.

In the LAA of existing LTE systems (e.g., Rel. 13), a data transmitting device transmits data to other devices (e.g., base station, user terminal, Wi-Fi device, etc.) before transmitting data in an unlicensed band. Performs LBT to confirm the presence or absence of transmission.

The transmitting device may be, for example, a base station (eg, gNB: gNodeB) in the downlink (DL), and a user terminal (eg, User Equipment (UE)) in the uplink (UL). Furthermore, the receiving device that receives data from the transmitting device may be, for example, a user terminal in DL, or a base station in UL.

In the LAA of an existing LTE system, the transmitting device starts data transmission after a predetermined period (e.g., immediately or during a backoff period) after the absence of transmission from other devices (idle state) is detected in the LBT. .

The following four categories are defined as channel access methods in LTE LAA.
-Category 1: The node transmits without performing LBT.
-Category 2: The node performs carrier sensing at a fixed sensing time before transmitting, and transmits when the channel is empty.
・Category 3: Before transmission, the node randomly generates a value (random backoff) from within a predetermined range, repeatedly performs carrier sensing in a fixed sensing slot time, and confirms that the channel is empty over the slot of the value. Send if confirmed.
・Category 4: Before transmission, the node randomly generates a value (random backoff) from within a predetermined range, repeatedly performs carrier sensing in a fixed sensing slot time, and confirms that the channel is free over the slot of the value. Send if confirmed. The node changes the range (contention window size) of the random backoff value depending on the communication failure situation due to a collision with communication of another system.

As an LBT rule, it is being considered to perform LBT according to the length of a gap between two transmissions (a non-transmission period, a period in which received power is below a predetermined threshold, etc.).

NR systems using unlicensed bands may be referred to as NR-Unlicensed (U) systems, NR LAA systems, etc. Dual connectivity (DC) between licensed bands and unlicensed bands, stand-alone (SA) of unlicensed bands, etc. may also be adopted in NR-U.

In NR-U, a base station (eg, gNB) or UE obtains a transmission opportunity (TxOP) and performs transmission when the LBT result is idle. The base station or UE does not transmit if the LBT result is busy (LBT-busy). The time of transmission opportunity is called Channel Occupancy Time (COT).

It is being considered that NR-U uses a signal including at least a Synchronization Signal (SS)/Physical Broadcast CHannel (PBCH) block (SS block (SSB)). The following is being considered in unlicensed band operation using this signal.
- there are no gaps in the time range in which the signal is transmitted in at least one beam - the occupied bandwidth is met - the channel occupation time of the signal is minimized - it facilitates rapid channel access. Characteristic

Also, Channel State Information (CSI)-Reference Signal (RS), SSB burst set (SSB set), and control resource set (CONtrol REsource SET: CORESET) associated with SSB in one continuous burst signal. and PDSCH are being considered. This signal may be called a Discovery Reference Signal (DRS, NR-U DRS, etc.).

The CORESET associated with the SSB may be referred to as Remaining Minimum System Information (RMSI)-CORESET, CORESET #0, etc. RMSI may be called System Information Block 1 (SIB1). The PDSCH associated with the SSB may be a PDSCH carrying RMSI (RMSI PDSCH) or having a CRC scrambled by the PDCCH (System Information (SI) - Radio Network Temporary Identifier (RNTI)) in the RMSI-CORESET. The PDSCH may be scheduled using PDSCH (DCI).

SSBs with different SSB indices may be transmitted using different beams (base station transmit beams). The SSB and its corresponding RMSI PDCCH and RMSI PDSCH may be transmitted using the same beam.

In order to coexist with other systems or operators, a node in the NR-U (eg, base station, UE) starts transmission after confirming that the channel is idle (idle) using LBT.

After a successful LBT, a node may continue transmitting for a certain period of time after starting transmission. However, if transmission is interrupted for a predetermined gap period or longer in the middle, another system may be using the channel, so LBT is required again before the next transmission. The period during which transmission can continue depends on the LBT category used or the priority class in LBT. The priority class may be contention window size for random backoff, etc. The shorter the LBT period (the higher the priority class), the shorter the time during which transmission can continue.

Nodes are required to transmit in wideband according to the transmission bandwidth rules in unlicensed bands. For example, the transmission bandwidth regulation in Europe is 80% or more of the system bandwidth. Narrowband transmissions can be undetected and collide with other systems or operators that perform LBT in wideband.

It is preferable that nodes transmit in as short a time as possible. By reducing the channel occupation time of each of the coexisting systems, the multiple systems can efficiently share resources.

The base station in NR-U uses SSBs of different beams (beam indexes, SSB indexes), RMSI PDCCHs (PDCCHs for RMSI PDSCH scheduling) and RMSI PDSCHs associated with the SSBs, using as wide a band as possible. It is preferable to send within a short period of time. Thereby, the base station can apply a high priority class (LBT category with a short LBT period) to SSB/RMSI (DRS) transmission, and can expect that LBT will succeed with a high probability. Base stations can easily meet transmission bandwidth regulations by transmitting in wideband. Furthermore, the base station can avoid interruptions in transmission by transmitting in a short period of time.

Setting the bandwidth (UE channel bandwidth) of the initial downlink (DL) bandwidth part (BWP) for NR-U to 20 MHz is being considered. This is because the channel bandwidth of Wi-Fi, which is a coexistence system, is 20 MHz. In this case, SSB, RMSI PDCCH, and RMSI PDSCH need to be included in the 20 MHz bandwidth.

In NR-U DRS, the absence of gaps in the transmission period of at least one beam can prevent other systems from interrupting the transmission period.

The NR-U DRS may be transmitted periodically regardless of whether there are active UEs or idle UEs. This allows the base station to periodically transmit the signals required for the channel access procedure using simple LBT, and the UE can quickly access the NR-U cell.

NR-U DRS packs signals into short periods of time to limit the number of required channel accesses and achieve short channel occupancy times. The NR-U DRS may support standalone (SA) NR-U.

<Wideband operation>
Bandwidths greater than 20 MHz may be supported in multiple serving cells for both downlink (DL) and uplink (UL). In NR-U, support for the serving cell to be configured with a bandwidth wider than 20 MHz is being considered.

For DL operation, the following options are being considered for intra-carrier bandwidth part (BWP) based operation with bandwidth wider than 20 MHz.
- Option 1a: Multiple BWPs are configured, multiple BWPs are activated, and PDSCH is transmitted on one or more BWPs.
- Option 1b: Multiple BWPs are configured, multiple BWPs are activated, and PDSCH is transmitted on a single BWP.
- Option 2: If multiple BWPs are configured, a single BWP is activated, and the Clear Channel Assessment (CCA) of the entire BWP is successful at the base station, the PDSCH is transmitted on the BWP.
- Option 3: Multiple BWPs are configured, a single BWP is activated, and the PDSCH is transmitted on the portion of the BWP where CCA was successful at the base station.

Here, CCA may be determined for each 20 MHz band.

The UE may assume the presence of a DMRS-like signal in the PDCCH or group common (GC-PDCCH) to detect transmission bursts from the serving base station. The PDCCH may be a PDCCH for one UE (UE-specific PDCCH, Regular PDCCH). The GC-PDCCH may be a PDCCH common to one or more UEs (UE group common PDCCH).

In unlicensed bands, transmission bursts may not be periodically transmitted due to LBT, so blind decoding (blind detection) is not required to detect transmission bursts in order to reduce UE power. It's okay. The UE may first perform DMRS detection, and when detecting DMRS, perform blind decoding. Such two-step blind decoding with DMRS detection may not be mandatory for the UE.

Among the above options, Rel. 15 Similar to NR, options 2 and 3 using a single active BWP have a small impact on the specification.

As shown in Figure 1 (transmission spectrum), if a single active BWP has four LBT subbands and option 2 (first downlink transmission method) is applied, the base station LBT is performed in each, and if all LBT results are idle (successful) (LBT result A), transmission in the active BWP can be performed. If the LBT result in any subband is busy (failure) (LBT result B), the base station does not transmit in the active BWP.

As shown in Figure 2 (transmission spectrum), if a single active BWP has four subbands and option 3 (second downlink transmission method) is applied, the base station If LBT is performed and all LBT results are idle, transmission in the active BWP can be performed. If the LBT result in any subband is busy, the base station may transmit in a subband other than that subband. Here, it is assumed that a single active BWP includes four consecutive subbands #0, #1, #2, and #3. If the LBT results in all subbands #0 to #3 are idle (LBT result A), the base station can perform transmission in consecutive subbands #0 to #3. If only the LBT result in subband #0 is busy (LBT result B), the base station can perform transmissions in consecutive subbands #1, #2, #3. If only the LBT result in subband #1 is busy (LBT result C), the base station can perform transmissions in subbands #0, #2, #3. The band between subbands #0 and #2 becomes a gap, and the transmittable band becomes discontinuous.

The LBT subband may have a predetermined bandwidth. The predetermined bandwidth may be one of the bandwidths defined for the coexistence system. For example, the predetermined bandwidth may be 20 MHz.

<PDCCH monitoring in NR-U>
In NR-U, the base station (eg, gNB) can transmit in a specific period after successfully performing LBT, and therefore cannot always perform DL transmission of the serving cell.

Even if the base station starts transmission immediately after successful LBT, the UE will not be able to notice the transmission unless it performs PDCCH monitoring at that timing, so it is possible to perform PDCCH monitoring at fine time granularity. . Increasing the frequency of PDCCH monitoring of the UE increases the power consumption of the UE. In addition, Rel. Using multiple PDCCH monitoring occasions within one slot in 15 is an optional feature.

Therefore, until DL transmission of the serving cell starts, the UE does not monitor the PDCCH, but rather monitors a reference signal such as DMRS, which can be monitored with lower power consumption, at a time granularity that is finer than the slot, and uses the reference signal. When detected, it is determined that DL transmission of the serving cell has started, and PDCCH monitoring with finer time granularity than the slot is being performed up to the next slot boundary (dynamic PDCCH monitoring).

As shown in FIG. 3, dynamic PDCCH monitoring may consist of three monitoring phases:
・Phase A: No PDCCH monitoring ・Phase B: Minislot PDCCH monitoring ・Phase C: Normal slot PDCCH monitoring

A minislot may have a shorter period (a predetermined number of symbols) than a slot.

Dynamic PDCCH monitoring can reduce the UE's load on PDCCH monitoring for the NR-U serving cell.

Phase A is a state in which no transmission bursts from the base station are being transmitted, eg, outside the base station's COT. In Phase A, the UE does not monitor the PDCCH, and the UE may monitor the DMRS of the GC-PDCCH. The UE may decide to transition from phase A to B by detecting a transmission burst with DMRS on the GC-PDCCH from the serving base station. If the expected number of DMRSs is small, the DMRS monitoring load on the UE can be reduced.

Phase B may be during the slot period in which the GC-PDCCH DMRS is detected. In this phase, the UE may monitor the DMRS on the PDCCH at the start of every minislot up to the next slot boundary. The UE may be aware of the duration of Phase B.

In phase B, that is, in the first slot of the transmission burst, the PDCCH transmission timing changes depending on the LBT success timing, and after the PDCCH and PDSCH of a predetermined length are transmitted, PDCCH and PDSCH are further transmitted in the remaining symbols. Therefore, it is preferable to set a plurality of PDCCH monitoring occasions.

After Phase B, the UE receives Rel. 15 Switch the monitoring phase to phase C, which monitors PDCCH according to the same search space settings as NR.

In phase C, that is, in the slots after the first slot in the transmission burst, scheduling similar to that for the NR frequency may be performed. For example, in the eMBB use case, a PDCCH may be placed at the beginning of each slot.

With this operation, channel access can be started immediately after LBT is successful, and an increase in power consumption of the UE due to PDCCH monitoring can be suppressed.

In LTE-LAA, the beginning of DL transmission is the boundary of a subframe (1 ms) or slot (0.5 ms). The beginning of DL transmission always includes a cell-specific reference signal (CRS). PDCCH is mapped to the entire component carrier (CC) band. For example, the UE is notified by a common PDCCH of information about the transmission in the subframe of that PDCCH and the next subframe (e.g., whether there is transmission or not, up to which symbol there is transmission, etc.). You may be notified or you may not be notified. Transmission of a common PDCCH is not mandatory.

The UE may blindly detect a CRS in a slot period, and when detecting a CRS, may blindly detect a PDCCH or a common PDCCH, or may perform blind detection of a CRS and a PDCCH in a slot period from the beginning.

In NR-U, it is being considered that areas other than slot boundaries may be allowed as the beginning of DL transmission. If the UE continues to monitor PDCCH and DMRS at a finer granularity than slots, the power consumption of the UE will increase.

If LBT is performed for each LBT subband (eg, 20 MHz), the CC or BWP bandwidth can be set wider than the LBT subband width. In that case, LBT is performed in multiple LBT subbands, and the band at the beginning of the transmission burst may differ depending on which LBT subband the LBT was successfully performed in. It is conceivable that the UE performs monitoring for each LBT subband.

Therefore, the present inventors came up with a method to shorten the time from LBT success to channel access and to suppress an increase in UE power consumption due to PDCCH monitoring.

It is preferable to narrow down the target signals for fine-grained monitoring. Preferably, monitoring at the beginning of the transmission burst is performed for each LBT subband, and monitoring at slots after the beginning slot of the transmission burst is performed in a band in which LBT is successful.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The wireless communication methods according to each embodiment may be applied singly or in combination.

In this disclosure, Listen Before Talk (LBT), listening, Clear Channel Assessment (CCA), carrier sense, channel sensing, sensing, channel access procedure, and shared spectrum channel access are interchangeable. It's okay.

In this disclosure, frequency, band, spectrum, carrier, component carrier (CC), and cell may be read interchangeably.

In this disclosure, NR-U frequency, NR-U target frequency, NR-U band, shared spectrum, unlicensed band, unlicensed spectrum, LAA SCell, LAA cell, primary cell: PCell, Primary Secondary Cell: PSCell, Special Cell: SpCell), Secondary Cell (SCell), and frequency band to which channel sensing is applied may be read interchangeably.

In this disclosure, NR frequency, NR target frequency, licensed band, licensed spectrum, PCell, PSCell, SpCell, SCell, non-NR-U frequency, Rel. 15, NR, and frequency band to which channel sensing is not applied may be read interchangeably.

Different frame structures may be used between the NR-U frequency and the NR frequency.

The wireless communication system (NR-U, LAA system) may conform to (support the first wireless communication standard) a first wireless communication standard (eg, NR, LTE, etc.).

Other systems (coexistence systems, coexistence devices) and other wireless communication devices (coexistence devices) that coexist with this wireless communication system include Wi-Fi, Bluetooth (registered trademark), WiGig (registered trademark), wireless LAN (Local Area Network), IEEE802.11, LPWA (Low Power Wide Area), or the like may be compliant with a second wireless communication standard (supporting the second wireless communication standard) that is different from the first wireless communication standard. The coexistence system may be a system that receives interference from a wireless communication system, or a system that causes interference to the wireless communication system.

In the present disclosure, transmission burst, DL transmission burst, DL transmission at the beginning of COT, and DL transmission from the base station may be read interchangeably.

In this disclosure, at least one of PDCCH and GC-PDCCH may be referred to as a specific PDCCH, PDCCH, etc. The DMRS for at least one of PDCCH and GC-PDCCH may be referred to as DMRS for PDCCH, DMRS, etc.

In this disclosure, the terms LBT subband, LBT band, active DL BWP portion, subband, and subband may be interchanged.

In this disclosure, monitoring, blind detection, blind decoding, and attempting detection may be used interchangeably.

(Wireless communication method)
<Embodiment 1>
A UE may be configured with multiple search space (SS) configurations, each having multiple different PDCCH monitoring periods. Based on the detection result of a specific PDCCH, the UE may decide whether or not to use a specific SS configuration among the multiple SS configurations (the specific SS configuration may be changed, the specific SS (You may change the settings.) The specific PDCCH may be at least one of GC-PDCCH and PDCCH. The particular SS configuration may be the SS configuration used for Phase A.

Phase A consists of the period up to (before) the detection of a specific PDCCH, the period after the serving base station is notified that the serving base station's transmission burst has been interrupted by the detected specific PDCCH, and The period may be at least one of a period after the end timing of the transmission burst, which is notified by the PDCCH, and a period in which DL transmission from the serving base station is not detected for a predetermined period of time.

Phase B may be from detection of a particular PDCCH to the first slot boundary.

Phase C may be after the first slot boundary after detecting a particular PDCCH.

The UE may be configured with two SS configurations (eg, SS #1, #2) for transmission burst detection. SS #1 and #2 may be UE-specific search spaces (USSs). SS #1 may be the default USS, or may be the SS used for phases A and B, and may have a monitoring period shorter than the slot length. SS #2 may be an SS used for phase C, and the monitoring period may be equal to the slot length.

FIG. 4 is a diagram illustrating an example of PDCCH monitoring using two SS configurations.

In Phases A and B, the UE may monitor SS#1 and not monitor SS#2.

In Phase C, the UE may monitor SS#2 and not monitor SS#1.

The UE may be configured with three SS configurations (eg, SS #0, #1, #2) for transmission burst detection. SS #0, #1, and #2 may be USS. SS #0 may be the default USS, or may be the SS used for phase A, and may have a monitoring period shorter than the slot length. SS #1 may be an SS used for phase B, and the monitoring period may be shorter than the slot length. SS #2 may be an SS used for phase C, and the monitoring period may be equal to the slot length.

FIG. 5 is a diagram illustrating an example of PDCCH monitoring using three SS configurations.

In Phase A, the UE may monitor SS #0 and not monitor SS #1 and #2.

Whether the UE monitors a specific PDCCH based on SS#0 may depend on the UE implementation. The UE may monitor only DMRS based on SS#0 and may not monitor a specific PDCCH based on SS#0.

In Phase B, the UE may monitor SS #1 and not monitor SS #0 and #2.

The PDCCH monitoring cycle in SS#1 may be different from the PDCCH monitoring cycle in SS#0. The PDCCH monitoring cycle in SS#1 may be longer than the PDCCH monitoring cycle in SS#0. For example, the PDCCH monitoring period in SS#0 may be 2 symbols, and the PDCCH monitoring period in SS#1 may be 4 symbols.

In Phase C, the UE may monitor SS #2 and not monitor SS #0 and #1.

The SS configuration for monitoring in at least one of Phase A and Phase B may be referred to as a first SS configuration. The SS configuration for monitoring in Phase C may be referred to as the second SS configuration.

The UE may be configured to distinguish SS settings for Phases A and B and SS settings for Phase C, or may be configured to distinguish between SS settings for Phase A, SS settings for Phase B, and SS settings for Phase C. The SS settings may be set separately. These SS settings may be distinguished by different RRC information elements (IEs) or by different field names.

The UE may determine the SS configuration to be monitored depending on whether the detection of a specific PDCCH is successful or not. For example, the UE may switch from the SS configuration for Phases A and B or the SS configuration for Phase B to the SS configuration for Phase C when detecting a specific PDCCH. In other words, the UE may be implicitly instructed to switch the SS configuration by a specific PDCCH.

The UE may switch the SS configuration based on an SS configuration switching instruction included in the DCI within a specific PDCCH. For example, when the UE detects a switching instruction, the UE may switch from the SS settings for Phases A and B or the SS settings for Phase B to the SS settings for Phase C. In other words, the UE may be explicitly instructed to switch the SS configuration by a specific PDCCH.

According to Embodiment 1, the PDCCH monitoring cycle until detecting a specific PDCCH is shorter than the PDCCH monitoring cycle after detecting the specific PDCCH, so that the period from the base station's LBT success to the start of transmission burst is Delays can be suppressed and frequency usage efficiency can be increased. Furthermore, power consumption can be reduced by increasing the PDCCH monitoring period after the UE detects a specific PDCCH.

<Embodiment 2>
The UE may monitor the GC-PDCCH on the NR-U frequency.

GC-PDCCH may be used for notification of transmission burst configuration on the NR-U frequency. For example, the GC-PDCCH may notify the slot format by a specific DCI format (eg, DCI format 2_0). The UE may know the length of the DL transmission based on the slot format.

The UE may perform GC-PDCCH monitoring according to either of the following GC-PDCCH monitoring 1 or 2.

《GC-PDCCH monitoring 1》
The UE may be configured by upper layer signaling whether the GC-PDCCH is transmitted on the NR-U frequency.

If the UE is configured with SS settings for GC-PDCCH, it may monitor the GC-PDCCH based on the configured SS settings. The SS configuration for GC-PDCCH may be a GC-PDCCH-dedicated SS configuration or a specific DCI format (e.g., DCI format 2_0, new DCI format for notification to a group of UEs, NR-U It may be an SS configuration including a new DCI format for the frequency. The UE may recognize the transmission burst configuration of the serving base station based on the GC-PDCCH detection result. The GC-PDCCH detection result may be whether or not the GC-PDCCH is detected, or may be the notification content of the detected GC-PDCCH (specific DCI format).

If the UE is not configured with SS configuration for GC-PDCCH, it may recognize whether there is a transmission from the serving base station based on the detection result of a particular DL transmission. The specific DL transmission may be at least one of a PDCCH, a DMRS, and a specific reference signal (RS, eg, CSI-RS). For example, the UE may recognize that there is a transmission from the serving base station if the SS configuration for the GC-PDCCH is not configured and it detects a specific DL transmission. For example, the UE may recognize that there is no transmission from the serving base station if the SS configuration for the GC-PDCCH is not configured and the UE does not detect a specific DL transmission.

《GC-PDCCH monitoring 2》
The UE may always be configured to monitor the GC-PDCCH on the NR-U frequency.

The UE is always configured with the SS configuration for GC-PDCCH for BWP of the NR-U frequency, and may monitor the GC-PDCCH based on the SS configuration. The UE may recognize the transmission burst configuration of the serving base station based on the GC-PDCCH detection result. The GC-PDCCH detection result may be whether or not the GC-PDCCH is detected, or may be the notification content of the detected GC-PDCCH (specific DCI format).

According to this embodiment 2, a UE using the NR-U frequency can reliably receive the GC-PDCCH at the beginning of a transmission burst. Also, the UE can be aware of the structure of the transmission burst.

<Embodiment 3>
The UE may be configured with a first CORESET associated with a first SS configuration to be monitored before detection of a specific PDCCH, and a second CORESET associated with a second SS configuration to be monitored after detection of a specific PDCCH. good. If the BWP bandwidth at the NR-U frequency is wider than the LBT sub-bandwidth, different rules may be defined for the first and second CORESETs.

Similar to Embodiment 1, the first SS configuration may be used for monitoring in at least one of Phase A and Phase B. The second SS configuration may be used for monitoring in Phase C.

The UE has a first SS configuration for pre-detection monitoring of a specific PDCCH, a first CORESET associated with the first SS configuration, a second SS configuration for post-detection monitoring of a specific PDCCH, and a second SS configuration. and an associated second CORESET.

Multiple CORESETs may be associated with one SS configuration.

Option 3 (second downlink transmission method) described above may be applied. The base station may perform LBT on each of a plurality of LBT subbands included in the BWP before transmitting the transmission burst, and may transmit the transmission burst using at least one of the LBT subbands on which LBT was successful. The base station may transmit the transmission burst using all LBT subbands in which LBT was successful, or may transmit the transmission burst using a preset LBT subband among the LBT subbands in which LBT was successful. You may.

When monitoring the first SS configuration, the UE does not know in which LBT subband the serving base station can transmit, so it may perform blind detection of PDCCH candidates for each LBT subband.

A plurality of first CORESETs, each mapped to a plurality of different LBT subbands in the BWP, may be associated with the first SS configuration.

At least one first CORESET mapped across different LBT subbands within the BWP may be associated with the first SS configuration. In this case, the UE may assume that the PDCCH candidates and DMRS are mapped within the corresponding LBT subbands. In other words, the UE may not assume that PDCCH candidates and DMRS are mapped across multiple LBT subbands.

When the UE monitors the second SS configuration, since it has already been determined in which LBT subband the serving base station can transmit, the base station may notify information regarding the LBT subband used for transmission. For example, the UE may be informed of the LBT subband configuration via a particular PDCCH.

A plurality of second CORESETs, each mapped to a plurality of different LBT subbands in the BWP, may be associated with the second SS configuration.

The UE may perform PDCCH monitoring using a second CORESET mapped to the LBT subband based on the detected specific PDCCH and a second SS configuration. For example, the LBT subband based on the detected specific PDCCH may be the LBT subband of the detected specific PDCCH, or may be the LBT subband signaled by the detected specific PDCCH. .

At least one second CORESET mapped across different LBT subbands within the BWP may be associated with the second SS configuration. In this case, the UE may assume that the PDCCH candidates and DMRS are mapped across at least one LBT subband. In other words, PDCCH candidates and DMRS may not be mapped within one LBT subband. When the PDCCH and DMRS in the second SS configuration are mapped across multiple LBT subbands, they can be mapped over a wider band than in the first SS configuration, so frequency diversity effects and channel estimation accuracy can be improved.

For switching from the first SS configuration to the second SS configuration, the UE selects the second CORESET associated with the second SS configuration, which corresponds to the LBT subband in which the LBT was successful, even if it is notified by a specific PDCCH. good. The UE may perform PDCCH monitoring using the notified second CORESET and second SS configuration.

According to this third embodiment, it is possible to receive DL transmission in a band wider than the LBT subband at the NR-U frequency.

<Embodiment 4>
In the UE that supports the NR-U frequency, at least one of dynamically switching (changing) the SS configuration to be monitored (Embodiment 1) and monitoring the GC-PDCCH (Embodiment 2) It may be a mandatory function.

In a UE that supports the NR-U frequency, both dynamically switching the SS configuration to be monitored and monitoring the GC-PDCCH may be essential functions.

In a UE supporting the NR-U frequency, monitoring of GC-PDCCH may be an essential function. Dynamically switching the SS settings to be monitored may be an optional function. The UE may report that it supports dynamically switching the monitored SS configuration as a UE capability.

According to the fourth embodiment, the UE can reliably perform at least one of dynamically switching the SS configuration to be monitored and monitoring the GC-PDCCH on the NR-U frequency. can.

(wireless communication system)
The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above-described embodiments of the present disclosure or a combination thereof.

FIG. 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc. specified by the Third Generation Partnership Project (3GPP). .

Furthermore, the wireless communication system 1 may support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC has dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), and dual connectivity between NR and LTE (NR-E -UTRA Dual Connectivity (NE-DC)).

In EN-DC, an LTE (E-UTRA) base station (eNB) is a master node (Master Node (MN)), and an NR base station (gNB) is a secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

The wireless communication system 1 has dual connectivity between multiple base stations within the same RAT (for example, NR-NR Dual Connectivity (NN-DC) where both the MN and SN are NR base stations (gNB)). )) may be supported.

The wireless communication system 1 includes a base station 11 that forms a macro cell C1 with relatively wide coverage, and base stations 12 (12a-12c) that are located within the macro cell C1 and form a small cell C2 that is narrower than the macro cell C1. You may prepare. User terminal 20 may be located within at least one cell. The arrangement, number, etc. of each cell and user terminal 20 are not limited to the embodiment shown in the figure. Hereinafter, when base stations 11 and 12 are not distinguished, they will be collectively referred to as base station 10.

The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using a plurality of component carriers (CC) and dual connectivity (DC).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). Macro cell C1 may be included in FR1, and small cell C2 may be included in FR2. For example, FR1 may be a frequency band below 6 GHz (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and FR1 may correspond to a higher frequency band than FR2, for example.

Further, the user terminal 20 may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

The plurality of base stations 10 may be connected by wire (for example, optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, base station 11, which is an upper-level station, is an Integrated Access Backhaul (IAB) donor, and base station 12, which is a relay station, is an IAB donor. May also be called a node.

Base station 10 may be connected to core network 30 via other base stations 10 or directly. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

The user terminal 20 may be a terminal compatible with at least one of communication systems such as LTE, LTE-A, and 5G.

In the wireless communication system 1, an orthogonal frequency division multiplexing (OFDM)-based wireless access method may be used. For example, in at least one of the downlink (DL) and uplink (UL), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

A wireless access scheme may be referred to as a waveform. Note that in the wireless communication system 1, other wireless access methods (for example, other single carrier transmission methods, other multicarrier transmission methods) may be used as the UL and DL radio access methods.

In the wireless communication system 1, downlink channels include a physical downlink shared channel (PDSCH) shared by each user terminal 20, a broadcast channel (physical broadcast channel (PBCH)), and a downlink control channel (physical downlink control channel). Channel (PDCCH)) or the like may be used.

In the wireless communication system 1, uplink channels include an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), and a random access channel. (Physical Random Access Channel (PRACH)) or the like may be used.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted through the PDSCH. User data, upper layer control information, etc. may be transmitted by PUSCH. Furthermore, a Master Information Block (MIB) may be transmitted via the PBCH.

Lower layer control information may be transmitted by PDCCH. The lower layer control information may include, for example, downlink control information (DCI) that includes scheduling information for at least one of PDSCH and PUSCH.

Note that the DCI that schedules PDSCH may be called DL assignment, DL DCI, etc., and the DCI that schedules PUSCH may be called UL grant, UL DCI, etc. Note that PDSCH may be replaced with DL data, and PUSCH may be replaced with UL data.

A control resource set (CORESET) and a search space may be used to detect the PDCCH. CORESET corresponds to a resource for searching DCI. The search space corresponds to a search area and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that "search space", "search space set", "search space setting", "search space set setting", "CORESET", "CORESET setting", etc. in the present disclosure may be read interchangeably.

PUCCH allows channel state information (CSI), delivery confirmation information (for example, may be called Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK/NACK, etc.), and scheduling request ( Uplink Control Information (UCI) including at least one of SR)) may be transmitted. A random access preamble for establishing a connection with a cell may be transmitted by PRACH.

Note that in the present disclosure, downlinks, uplinks, etc. may be expressed without adding "link". Furthermore, various channels may be expressed without adding "Physical" at the beginning.

In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), and the like may be transmitted. In the wireless communication system 1, the DL-RS includes a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), and a demodulation reference signal (DeModulation). Reference Signal (DMRS)), Positioning Reference Signal (PRS), Phase Tracking Reference Signal (PTRS), etc. may be transmitted.

The synchronization signal may be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block including SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS/PBCH block, SS Block (SSB), etc. Note that SS, SSB, etc. may also be called reference signals.

In addition, in the wireless communication system 1, measurement reference signals (Sounding Reference Signal (SRS)), demodulation reference signals (DMRS), etc. are transmitted as uplink reference signals (UL-RS). good. Note that DMRS may be called a user terminal-specific reference signal (UE-specific reference signal).

(base station)
FIG. 7 is a diagram illustrating an example of the configuration of a base station according to an embodiment. The base station 10 includes a control section 110, a transmitting/receiving section 120, a transmitting/receiving antenna 130, and a transmission line interface 140. Note that one or more of each of the control unit 110, the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140 may be provided.

Note that this example mainly shows functional blocks that are characteristic of the present embodiment, and it may be assumed that base station 10 also has other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

The control unit 110 controls the base station 10 as a whole. The control unit 110 can be configured from a controller, a control circuit, etc., which will be explained based on common recognition in the technical field related to the present disclosure.

The control unit 110 may control signal generation, scheduling (eg, resource allocation, mapping), and the like. The control unit 110 may control transmission and reception, measurement, etc. using the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140. The control unit 110 may generate data, control information, a sequence, etc. to be transmitted as a signal, and may transfer the generated data to the transmitting/receiving unit 120. The control unit 110 may perform communication channel call processing (setting, release, etc.), status management of the base station 10, radio resource management, and the like.

The transmitting/receiving section 120 may include a baseband section 121, a radio frequency (RF) section 122, and a measuring section 123. The baseband section 121 may include a transmission processing section 1211 and a reception processing section 1212. The transmitting/receiving unit 120 includes a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measuring circuit, a transmitting/receiving circuit, etc., which are explained based on common understanding in the technical field related to the present disclosure. be able to.

The transmitter/receiver 120 may be configured as an integrated transmitter/receiver, or may be configured from a transmitter and a receiver. The transmitting section may include a transmitting processing section 1211 and an RF section 122. The reception section may include a reception processing section 1212, an RF section 122, and a measurement section 123.

The transmitting/receiving antenna 130 can be configured from an antenna described based on common recognition in the technical field related to the present disclosure, such as an array antenna.

The transmitter/receiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitter/receiver 120 may receive the above-mentioned uplink channel, uplink reference signal, and the like.

The transmitting/receiving unit 120 may form at least one of a transmitting beam and a receiving beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

The transmitting/receiving unit 120 (transmission processing unit 1211) performs Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (for example, on the data, control information, etc. acquired from the control unit 110). RLC retransmission control), Medium Access Control (MAC) layer processing (for example, HARQ retransmission control), etc. may be performed to generate a bit string to be transmitted.

The transmitting/receiving unit 120 (transmission processing unit 1211) performs channel encoding (which may include error correction encoding), modulation, mapping, filter processing, and discrete Fourier transform (DFT) on the bit string to be transmitted. A baseband signal may be output after performing transmission processing such as processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion.

The transmitting/receiving unit 120 (RF unit 122) may perform modulation, filter processing, amplification, etc. on the baseband signal in a radio frequency band, and may transmit the signal in the radio frequency band via the transmitting/receiving antenna 130. .

On the other hand, the transmitting/receiving section 120 (RF section 122) may perform amplification, filter processing, demodulation into a baseband signal, etc. on the radio frequency band signal received by the transmitting/receiving antenna 130.

The transmitting/receiving unit 120 (reception processing unit 1212) performs analog-to-digital conversion, fast Fourier transform (FFT) processing, and inverse discrete Fourier transform (IDFT) on the acquired baseband signal. )) processing (if necessary), applying reception processing such as filter processing, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing and PDCP layer processing, User data etc. may also be acquired.

The transmitting/receiving unit 120 (measuring unit 123) may perform measurements regarding the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurement, Channel State Information (CSI) measurement, etc. based on the received signal. The measurement unit 123 measures reception power (for example, Reference Signal Received Power (RSRP)), reception quality (for example, Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)). , signal strength (for example, Received Signal Strength Indicator (RSSI)), propagation path information (for example, CSI), etc. may be measured. The measurement results may be output to the control unit 110.

The transmission path interface 140 transmits and receives signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and transmits and receives user data (user plane data) for the user terminal 20, control plane It is also possible to acquire and transmit data.

Note that the transmitting unit and receiving unit of the base station 10 in the present disclosure may be configured by at least one of the transmitting/receiving unit 120 and the transmitting/receiving antenna 130.

(user terminal)
FIG. 8 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. The user terminal 20 includes a control section 210, a transmitting/receiving section 220, and a transmitting/receiving antenna 230. Note that one or more of each of the control unit 210, the transmitting/receiving unit 220, and the transmitting/receiving antenna 230 may be provided.

Note that this example mainly shows functional blocks that are characteristic of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which will be explained based on common recognition in the technical field related to the present disclosure.

The control unit 210 may control signal generation, mapping, and the like. The control unit 210 may control transmission and reception using the transmitting/receiving unit 220 and the transmitting/receiving antenna 230, measurement, and the like. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as a signal, and may transfer the generated data to the transmitting/receiving unit 220.

The transmitting/receiving section 220 may include a baseband section 221, an RF section 222, and a measuring section 223. The baseband section 221 may include a transmission processing section 2211 and a reception processing section 2212. The transmitting/receiving unit 220 can be configured from a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measuring circuit, a transmitting/receiving circuit, etc., which are explained based on common recognition in the technical field related to the present disclosure.

The transmitting/receiving section 220 may be configured as an integrated transmitting/receiving section, or may be configured from a transmitting section and a receiving section. The transmitting section may include a transmitting processing section 2211 and an RF section 222. The reception section may include a reception processing section 2212, an RF section 222, and a measurement section 223.

The transmitting/receiving antenna 230 can be configured from an antenna described based on common recognition in the technical field related to the present disclosure, such as an array antenna.

The transmitter/receiver 220 may receive the above-described downlink channel, synchronization signal, downlink reference signal, and the like. The transmitter/receiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, and the like.

The transmitting/receiving unit 220 may form at least one of a transmitting beam and a receiving beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

The transmission/reception unit 220 (transmission processing unit 2211) performs PDCP layer processing, RLC layer processing (e.g. RLC retransmission control), MAC layer processing (e.g. , HARQ retransmission control), etc., to generate a bit string to be transmitted.

The transmitting/receiving unit 220 (transmission processing unit 2211) performs channel encoding (which may include error correction encoding), modulation, mapping, filter processing, DFT processing (as necessary), and IFFT processing on the bit string to be transmitted. , precoding, digital-to-analog conversion, etc., and output a baseband signal.

Note that whether or not to apply DFT processing may be based on the settings of transform precoding. When transform precoding is enabled for a certain channel (for example, PUSCH), the transmitting/receiving unit 220 (transmission processing unit 2211) performs the above processing in order to transmit the channel using the DFT-s-OFDM waveform. DFT processing may be performed as the transmission processing, or if not, DFT processing may not be performed as the transmission processing.

The transmitting/receiving unit 220 (RF unit 222) may perform modulation, filter processing, amplification, etc. on the baseband signal in a radio frequency band, and may transmit the signal in the radio frequency band via the transmitting/receiving antenna 230. .

On the other hand, the transmitting/receiving section 220 (RF section 222) may perform amplification, filter processing, demodulation into a baseband signal, etc. on the radio frequency band signal received by the transmitting/receiving antenna 230.

The transmission/reception unit 220 (reception processing unit 2212) performs analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filter processing, demapping, demodulation, and decoding (error correction) on the acquired baseband signal. (which may include decoding), MAC layer processing, RLC layer processing, and PDCP layer processing may be applied to obtain user data and the like.

The transmitting/receiving section 220 (measuring section 223) may perform measurements regarding the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (for example, RSRP), reception quality (for example, RSRQ, SINR, SNR), signal strength (for example, RSSI), propagation path information (for example, CSI), and the like. The measurement results may be output to the control unit 210.

Note that the transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting/receiving unit 220, the transmitting/receiving antenna 230, and the transmission path interface 240.

The transmitting/receiving unit 220 may monitor the first downlink control channel based on search space (SS) settings for the frequency band to which channel sensing is applied. The control unit 210 may change the search space setting based on the detection result of the first downlink control channel.

The control unit 210 uses the first search space setting to monitor the first downlink control channel, and uses the second search space setting to monitor the second downlink control channel after detecting the first downlink control channel. Good too. The monitoring period in the second search space setting may be longer than the monitoring period in the first search space setting.

Sensing may be performed in each of a plurality of subbands within a bandwidth portion (BWP) including the band of the first downlink control channel. At least one first control resource set (CORESET) associated with the first search space configuration may be mapped to the plurality of subbands. At least one second CORESET associated with the second search space configuration may be mapped to a subband based on the first downlink control channel among the plurality of subbands.

The first downlink control channel may be a group common downlink control channel (eg, GC-PDCCH).

The control unit 210 may have at least one of monitoring a group common downlink control channel and changing the search space setting based on the detection result as an essential function.

(Hardware configuration)
It should be noted that the block diagram used to explain the above embodiment shows blocks in functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or may be realized using two or more physically or logically separated devices directly or indirectly (e.g. , wired, wireless, etc.) and may be realized using a plurality of these devices. The functional block may be realized by combining software with the one device or the plurality of devices.

Here, functions include judgment, decision, judgement, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and consideration. , broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc. Not limited. For example, a functional block (configuration unit) that performs transmission may be called a transmitting unit, a transmitter, or the like. In either case, as described above, the implementation method is not particularly limited.

For example, a base station, a user terminal, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The base station 10 and user terminal 20 described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc. .

Note that in the present disclosure, words such as apparatus, circuit, device, section, unit, etc. can be read interchangeably. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of each device shown in the figure, or may be configured not to include some of the devices.

For example, although only one processor 1001 is shown, there may be multiple processors. Also, the processing may be performed by one processor, or the processing may be performed by two or more processors simultaneously, sequentially, or using other techniques. Note that the processor 1001 may be implemented using one or more chips.

Each function in the base station 10 and the user terminal 20 is performed by, for example, loading predetermined software (program) onto hardware such as a processor 1001 and a memory 1002, so that the processor 1001 performs calculations and communicates via the communication device 1004. This is achieved by controlling at least one of reading and writing data in the memory 1002 and storage 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) that includes interfaces with peripheral devices, a control device, an arithmetic device, registers, and the like. For example, at least a portion of the above-mentioned control unit 110 (210), transmitting/receiving unit 120 (220), etc. may be realized by the processor 1001.

Furthermore, the processor 1001 reads programs (program codes), software modules, data, and the like from at least one of the storage 1003 and the communication device 1004 to the memory 1002, and executes various processes in accordance with these. As the program, a program that causes a computer to execute at least part of the operations described in the above embodiments is used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operated in the processor 1001, and other functional blocks may also be realized in the same way.

Memory 1002 is a computer-readable storage medium, such as at least Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. It may be composed of one. Memory 1002 may be called a register, cache, main memory, or the like. The memory 1002 can store executable programs (program codes), software modules, and the like to implement a wireless communication method according to an embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, such as a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disk (CD-ROM), etc.), a digital versatile disk, removable disk, hard disk drive, smart card, flash memory device (e.g., card, stick, key drive), magnetic stripe, database, server, or other suitable storage medium. It may be configured by Storage 1003 may also be called an auxiliary storage device.

The communication device 1004 is hardware (transmission/reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be configured to include. For example, the above-described transmitting/receiving unit 120 (220), transmitting/receiving antenna 130 (230), etc. may be realized by the communication device 1004. The transmitter/receiver 120 (220) may be physically or logically separated into a transmitter 120a (220a) and a receiver 120b (220b).

The input device 1005 is an input device (eg, keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Further, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses for each device.

The base station 10 and the user terminal 20 also include a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc. It may be configured to include hardware, and a part or all of each functional block may be realized using the hardware. For example, processor 1001 may be implemented using at least one of these hardwares.

(Modified example)
Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, channel, symbol and signal may be interchanged. Also, the signal may be a message. The reference signal may also be abbreviated as RS, and may be called a pilot, pilot signal, etc. depending on the applicable standard. Further, a component carrier (CC) may be called a cell, a frequency carrier, a carrier frequency, or the like.

A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology includes, for example, subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, and radio frame configuration. , a specific filtering process performed by the transceiver in the frequency domain, a specific windowing process performed by the transceiver in the time domain, etc.

A slot may be constituted by one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. Furthermore, a slot may be a time unit based on numerology.

A slot may include multiple minislots. Each minislot may be made up of one or more symbols in the time domain. Furthermore, a mini-slot may also be called a sub-slot. A minislot may be made up of fewer symbols than a slot. PDSCH (or PUSCH) transmitted in time units larger than minislots may be referred to as PDSCH (PUSCH) mapping type A. PDSCH (or PUSCH) transmitted using minislots may be referred to as PDSCH (PUSCH) mapping type B.

Radio frames, subframes, slots, minislots, and symbols all represent time units for transmitting signals. Other names may be used for the radio frame, subframe, slot, minislot, and symbol. Note that time units such as frames, subframes, slots, minislots, and symbols in the present disclosure may be read interchangeably.

For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, and one slot or minislot may be called a TTI. In other words, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. It may be. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, a base station performs scheduling to allocate radio resources (frequency bandwidth, transmission power, etc. that can be used by each user terminal) to each user terminal on a TTI basis. Note that the definition of TTI is not limited to this.

The TTI may be a transmission time unit of a channel-coded data packet (transport block), a code block, a codeword, etc., or may be a processing unit of scheduling, link adaptation, etc. Note that when a TTI is given, the time interval (for example, the number of symbols) to which transport blocks, code blocks, code words, etc. are actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is called a TTI, one or more TTIs (that is, one or more slots or one or more minislots) may be the minimum time unit for scheduling. Further, the number of slots (minislot number) that constitutes the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI that is shorter than a normal TTI may be referred to as an abbreviated TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, or the like.

Note that long TTI (for example, normal TTI, subframe, etc.) may be read as TTI with a time length exceeding 1 ms, and short TTI (for example, short TTI, etc.) It may also be read as a TTI having the above TTI length.

A resource block (RB) is a unit of resource allocation in the time domain and frequency domain, and may include one or more continuous subcarriers (subcarriers) in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, and may be 12, for example. The number of subcarriers included in an RB may be determined based on numerology.

Additionally, an RB may include one or more symbols in the time domain and may be one slot, one minislot, one subframe, or one TTI long. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

Note that one or more RBs include a physical resource block (Physical RB (PRB)), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, and an RB. They may also be called pairs.

Further, a resource block may be configured by one or more resource elements (REs). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (also called partial bandwidth, etc.) refers to a subset of contiguous common resource blocks (RBs) for a certain numerology in a certain carrier. Good too. Here, the common RB may be specified by an RB index based on a common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be configured within one carrier for a UE.

At least one of the configured BWPs may be active and the UE may not expect to transmit or receive a given signal/channel outside of the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

Note that the structures of the radio frame, subframe, slot, minislot, symbol, etc. described above are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of symbols included in an RB, The number of subcarriers, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

In addition, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values from a predetermined value, or using other corresponding information. may be expressed. For example, radio resources may be indicated by a predetermined index.

The names used for parameters and the like in this disclosure are not limiting in any respect. Furthermore, the mathematical formulas etc. using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable designation, the various names assigned to these various channels and information elements are not in any way exclusive designations. .

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be referred to throughout the above description, may refer to voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may also be represented by a combination of

Further, information, signals, etc. may be output from the upper layer to the lower layer and from the lower layer to at least one of the upper layer. Information, signals, etc. may be input and output via multiple network nodes.

Input/output information, signals, etc. may be stored in a specific location (eg, memory) or may be managed using a management table. Information, signals, etc. that are input and output can be overwritten, updated, or added. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

Notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. For example, the information notification in this disclosure may be performed using physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), etc.), Medium Access Control (MAC) signaling), other signals, or a combination thereof. It may be carried out by

Note that the physical layer signaling may be called Layer 1/Layer 2 (L1/L2) control information (L1/L2 control signal), L1 control information (L1 control signal), etc. Further, RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like. Further, MAC signaling may be notified using, for example, a MAC Control Element (CE).

Further, notification of prescribed information (for example, notification of "X") is not limited to explicit notification, but may be made implicitly (for example, by not notifying the prescribed information or by providing other information) (by notification).

The determination may be made by a value expressed by 1 bit (0 or 1), or by a boolean value expressed by true or false. , may be performed by numerical comparison (for example, comparison with a predetermined value).

Software includes instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, whether referred to as software, firmware, middleware, microcode, hardware description language, or by any other name. , should be broadly construed to mean an application, software application, software package, routine, subroutine, object, executable, thread of execution, procedure, function, etc.

Additionally, software, instructions, information, etc. may be sent and received via a transmission medium. For example, if the software uses wired technology (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and/or wireless technology (such as infrared, microwave) to , a server, or other remote source, these wired and/or wireless technologies are included within the definition of a transmission medium.

As used in this disclosure, the terms "system" and "network" may be used interchangeably. "Network" may refer to devices (eg, base stations) included in the network.

In this disclosure, "precoding", "precoder", "weight (precoding weight)", "quasi-co-location (QCL)", "Transmission Configuration Indication state (TCI state)", "spatial "spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", Terms such as "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", and "panel" are interchangeable. can be used.

In this disclosure, "Base Station (BS)", "Wireless base station", "Fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission/Reception Point (TRP)", "Panel" , "cell," "sector," "cell group," "carrier," "component carrier," and the like may be used interchangeably. A base station may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

A base station can accommodate one or more (eg, three) cells. If a base station accommodates multiple cells, the overall coverage area of the base station can be partitioned into multiple smaller areas, and each smaller area is divided into base station subsystems (e.g., small indoor base stations (Remote Radio Communication services can also be provided by the Head (RRH)). The term "cell" or "sector" refers to part or all of the coverage area of a base station and/or base station subsystem that provides communication services in this coverage.

In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" are used interchangeably. can be done.

A mobile station is a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal. , handset, user agent, mobile client, client, or some other suitable terminology.

At least one of a base station and a mobile station may be called a transmitting device, a receiving device, a wireless communication device, or the like. Note that at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, or the like. The moving object may be a vehicle (for example, a car, an airplane, etc.), an unmanned moving object (for example, a drone, a self-driving car, etc.), or a robot (manned or unmanned). ). Note that at least one of the base station and the mobile station includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

Furthermore, the base station in the present disclosure may be replaced by a user terminal. For example, communication between a base station and a user terminal is replaced with communication between multiple user terminals (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Regarding the configuration, each aspect/embodiment of the present disclosure may be applied. In this case, the user terminal 20 may have the functions that the base station 10 described above has. Further, words such as "upstream" and "downstream" may be replaced with words corresponding to inter-terminal communication (for example, "side"). For example, uplink channels, downlink channels, etc. may be replaced with side channels.

Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station 10 may have the functions that the user terminal 20 described above has.

In this disclosure, the operations performed by the base station may be performed by its upper node in some cases. In a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (e.g. It is clear that this can be done by a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc. (but not limited to these) or a combination thereof.

Each aspect/embodiment described in this disclosure may be used alone, may be used in combination, or may be switched and used in accordance with execution. Further, the order of the processing procedures, sequences, flowcharts, etc. of each aspect/embodiment described in this disclosure may be changed as long as there is no contradiction. For example, the methods described in this disclosure use an example order to present elements of the various steps and are not limited to the particular order presented.

Each aspect/embodiment described in this disclosure is applicable to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system ( 4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802. 20, Ultra-WideBand (UWB), Bluetooth (registered trademark), and other appropriate wireless communication methods, and next-generation systems expanded based on these may be applied. Furthermore, a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G) may be applied.

As used in this disclosure, the phrase "based on" does not mean "based solely on" unless explicitly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

As used in this disclosure, any reference to elements using the designations "first," "second," etc. does not generally limit the amount or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, reference to a first and second element does not imply that only two elements may be employed or that the first element must precede the second element in any way.

As used in this disclosure, the term "determining" may encompass a wide variety of actions. For example, "judgment" can mean judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry ( For example, searching in a table, database, or other data structure), ascertaining, etc. may be considered to be "determining."

In addition, "judgment (decision)" includes receiving (e.g., receiving information), transmitting (e.g., sending information), input (input), output (output), access ( may be considered to be "determining", such as accessing data in memory (eg, accessing data in memory).

In addition, "judgment" is considered to mean "judging" resolving, selecting, choosing, establishing, comparing, etc. Good too. In other words, "judgment (decision)" may be considered to be "judgment (decision)" of some action.

Further, "judgment (decision)" may be read as "assuming", "expecting", "considering", etc.

"Maximum transmit power" as described in this disclosure may mean the maximum value of transmit power, the nominal maximum transmit power (the UE maximum transmit power), or the rated maximum transmit power (the UE maximum transmit power). rated UE maximum transmit power).

As used in this disclosure, the terms "connected", "coupled", or any variations thereof refer to any connection or coupling, direct or indirect, between two or more elements. can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access."

In this disclosure, when two elements are connected, they may be connected using one or more electrical wires, cables, printed electrical connections, etc., as well as in the radio frequency domain, microwave can be considered to be "connected" or "coupled" to each other using electromagnetic energy having wavelengths in the light (both visible and invisible) range.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." Note that the term may also mean that "A and B are each different from C". Terms such as "separate" and "coupled" may also be interpreted similarly to "different."

Where "include", "including" and variations thereof are used in this disclosure, these terms are inclusive, as is the term "comprising". It is intended that Furthermore, the term "or" as used in this disclosure is not intended to be exclusive or.

In this disclosure, when articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are plural.

Although the invention according to the present disclosure has been described in detail above, it is clear for those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the invention as determined based on the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and does not have any limiting meaning on the invention according to the present disclosure.

Claims (6)

a receiving unit that receives a first setting corresponding to one or more first search spaces and a second setting corresponding to one or more second search spaces;
Based on the detection of a downlink control information (DCI) format, one of the first configuration and the second configuration is determined, and a physical downlink control channel (PDCCH) is determined according to a search space corresponding to the configuration. a control unit for controlling monitoring of the
The DCI format is used by terminals to indicate the length of time used for transmission in the shared spectrum . 2. The terminal of claim 1, wherein the DCI format includes instructions for switching between the one or more first search spaces and the one or more second search spaces. The terminal according to claim 1, wherein the DCI format is used for instructions common to a group of terminals. receiving a first configuration corresponding to one or more first search spaces and a second configuration corresponding to one or more second search spaces;
Based on the detection of a downlink control information (DCI) format, one of the first configuration and the second configuration is determined, and a physical downlink control channel (PDCCH) is determined according to a search space corresponding to the configuration. controlling the monitoring of the
The DCI format is a wireless communication method for terminals that is used to indicate the length of time used for transmission in a shared spectrum . a transmitter that transmits a first setting corresponding to one or more first search spaces and a second setting corresponding to one or more second search spaces;
a control unit that controls transmission of a downlink control information (DCI) format used for determining one of the first setting and the second setting,
a physical downlink control channel (PDCCH) is monitored according to a search space corresponding to the configuration ;
The DCI format is used by the base station to indicate the length of time used for transmission in the shared spectrum . A system having a terminal and a base station,
The terminal is
a receiving unit that receives a first setting corresponding to one or more first search spaces and a second setting corresponding to one or more second search spaces;
Based on the detection of a downlink control information (DCI) format, one of the first configuration and the second configuration is determined, and a physical downlink control channel (PDCCH) is determined according to a search space corresponding to the configuration. a control unit for controlling monitoring of the
the base station transmits the first configuration and the second configuration, and transmits the DCI format ;
The system in which the DCI format is used to indicate the length of time used for transmission on a shared spectrum .

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